Child resistant closures

ABSTRACT

A threaded safety closure assembly for sealing threaded bottles or other containers with contents which might be harmful to children, the closure assembly including an inner cap and an overcap rotatable relative to the inner cap in unscrewing direction, as counterclockwise, except with selected pressure applied by an adult to effect interengagement between the two caps for opening movement thereof in unison permitting intentional access to the container contents; and the closure assembly having improved top drive interengagement between the caps in the closing direction, as clockwise, for use in capping machines applying a relatively high torque for effectively sealing the containers in hermetic fashion without tendency for the interengaged drive to frictionally weld or set under the applied torque and permit, as a result thereof, opening rotation of the closure assembly and rendering of the safety features inoperative for the intended purpose.

United States Patent 1 Curry et al.

111 3,8,78,9 ,5 Apr. 22, 1975 CHILD RESISTANT CLOSURES [75] Inventors:John Joseph Curry, Westchester; Carl William Lange, Des Plaines, both of111.

[73] Assignee: Illinois Tool Works Inc., Chicago.

[22] Filed: Dec. 28, 1973 [21] Appl. No.: 429,463

[52] 0.8. CI. 215/219 [51] Int. Cl..... B65d /02; Bd /56; A6lj 1/00 [58]Field of Search 215/9, 219, 220

[56] References Cited UNITED STATES PATENTS 3,679,085 7/1972 Ciach215/220 3.830.390 8/1974 Gach 215/9 Primary Examiner-George T. HallAttorney, Agent, or Firm-Robert W. Beart; Edward L. Benno 5 7 ABSTRACT Athreaded safety closure assembly for sealing threaded bottles or othercontainers with contents which might be harmful to children. theclosure'assembly including an inner cap and an overcap rotatablerelative to the inner cap in unscrewing direction, as counterclockwise,except with selected pressure applied by an adult to effectinterengagement between the two caps for opening movement thereof inunison permitting intentional access to the container contents; and theclosure assembly having improved top drive interengagement between thecaps in the closing direction, as clockwise, for use in capping machinesapplying a relatively high torque for effectively sealing the containersin hermetic fashion without tendency for the interengaged drive tofrictionally weld or set under the applied torque and permit. as aresult thereof, opening rotation of the closure assembly and renderingof the safety features inoperative for the intended purpose.

9 Claims, 8 Drawing Figures l l 22 2s I4 38 l2 6,. IO I I!" V CHILDRESISTANT CLOSURES The present invention is concerned with a safetyclosure assembly formed 'of suitable plastic material. preferablyaresilient material, and including an internally threaded inner cap andan overcap with engageable driving abutments between the tops of thecaps brought into operation byautomatic capping machines applyingrelatively high torque to threadedly engage the closure assembly with abottle or other container for hermetically sealing the same withprovision made for guarding against jamming or fixation between thedriving abutments under the applied torque so as to insure properfunctioning of adult manipulation of the overcap to effect engagementthereof with the inner cap for turning the two caps as a unit assemblyin a counterclockwise direction for unscrewing the same for thecontainer.

In the prior art, there are many forms of safety closures designed toprevent or render it difficult for children to remove the same frombottles and the like containing medicines or other contents which mightbe harmful without supervision. There are those requiring implements forremoving the closures and those requiring some undisclosed, and notreadily apparent manipulation of the closure before it can be removed orunscrewed from the associated container, and various other types. Amongthose requiring some manipulation of the closure, there is the typeincluding an inner cap for threaded engagement with a container and anovercap which will rotate relative to the inner cap in counterclockwiseunscrewing direction but which may be manipulated by an adult to effectinterengagement between the two caps for opening rotation of the closureassembly. This interengagement between two caps is often accomplished bysome axial movement of the overcap relative to the inner cap or by asqueezing pressure application of force to selected portions of theovercap. In the latter type, there is often no provision made for theapplication of high torque closing of the container in automatic cappingmachines in a manner which will insure proper functioning of the safetyopening arrangement for gaining intentional access to the contents ofthe container.

An object of the invention is to provide a threaded safety closureassembly of the double cap type which may be initially applied to acontainer under relatively high torque for hermetic sealing by automaticcapping machines without affecting the later functioning of safetyopening by manipulation of the overcap to effect opening rotation of theclosure assembly.

Another object of the invention is to provide a safety closure assemblyof the above type with interengageable driving abutment means betweenthe top of the two caps and through which the caps are rotated in unisonin the closing direction by the capping machines but with the abutmentmeans relieved along their trailing surfaces to present onlysubstantially line contact with the adjacent surfaces of the inner capand overcap, respectively, thus reducing to a minimum frictional surfaceengagement which might tend to set under storage conditions or underhigh top loading and handling conditions.

A further object of the invention is to provide a safety closure of theabove type wherein the cap skirts are provided with interengaging meansupon pressure application to "the overcap skirt for opening rotation ofthe closure assembly and with permissive trapped axial movement of theovercap relative to the inner cap upon opening direction rotation of theovercap relative to the inner with the driving abutments ratcheting byone another.

The above and other objects of the invention will in part be obvious andwill be hereinafter more fully pointed out in the following detaileddescription of the drawings in which FIG. 1 is a perspective view,partly in section, showing one form of closure assembly in sealedposition on a bottle;

FIG. 2 is a top plan view of the inner cap;

FIG. 3 is a side elevation, partly in section on the line 3-3 of FIG. 2,of the inner cap;

FIG. 4 is a top plan view, partly in section, of the overcap; 7

FIG. 5 is a fragmentary sectional view showing the axially elevatedposition of the overcap as the driving abutments ratchet by one anotherupon opening direction rotation of the overcap relative to the innercap;

FIG. 6 is a top plan view of a modified form of overcap;

FIG. 7 is a perspective view, partly in section, showing the overcap ofFIG. 6 in the closure assembly in sealed position on a bottle, and

FIG. 8 is a fragmentary sectional view, similar to FIG. 5, showing theaxially elevated position of the closure assembly of FIG. 7.

With reference to the drawings, and particularly FIGS. 1 to 4 at thistime, the closure assembly is shown applied to a bottle 10 (FIG. ll)having a neck portion 12 with external threads 14. The safety closureassembly includes an inner cap 16 nested within an outer or overcap 18formed of suitable materials such as metals or plastics. In onepreferred embodiment a plastic such as polypropylene was used for theinner cap and a resilient material such as polyethylene was used for theouter cap. The inner cap includesa top closing wall 20 with the innersurface recessed to receivea suitable sealing disc or liner 22 of pulpand vinylite adhered therein and adapted to hermetically seal thebottleby engagement with the lip: of the bottle neck 12. The inner caphas a depending skirt or flange 24 terminating in an outward shoulder 26which need not be peripherally continuous and the inner surface of theskirt is provided with thread formations 28 cooperating with the threads14 on the bottle neck. The outer surface of the skirt 24 is providedwith circumferentially spaced vertically extending ribs 25 serving asteeth for engagement with cooperating means on the outer cap as will beexplained. The outer surface of the closing wall 20 is provided with aperipheral upstanding rib'30 serving as the primary support for theouter cap, and upstanding spaced lugs or teeth 32 which serve as drivingabutment means for tightening the: inner cap in the closing direction ofrotation thereof as will be described hereinafter. These driving lugs orteeth may vary in number and circumferential spacing and each isprovided with a substantially vertical abutment surface 32a and a curveddownwardly or otherwise relieved leading surface 32b as shown in FIG. 3.

The outer or overcap 18 has atop closing wall 34 and a dependingperipheral skirt or flange 36 with a lower wall portion 38 of lesserthickness and more resiliency which terminates in an inwardly projectingshoulder 40 which need not be peripherally continuous and which normallyunderlies the shoulder 26 on the skirt of the inner cap. In turn, theinner surface of the top closing wall 34 of the overcap is provided withdependent spaced driving lugs or teeth 42 cooperating with the lugs 32on the inner cap and each lug 42 is shaped similarly to-the lugs 32 butin opposite direction, that is, with a vertical abutment surface 420 andrelieved trailing surface 42b. Sections at the periphery of the topclosing wall 34 of the overcap are weakened as by reducing the crosssection thereof for upward bowing or by cutting away narrow arcuatesections to provide slots 44 (FIG. 4) and similarly located sections ofthe skirt 36 arereduced in thickness, as at 46. This reduced thicknesswall section 46 is provided with internal vertically extending ribs orteeth 48 to cooperate with the teeth 25 on the inner cap as will beexplained. The reduced wall section 46 is provided with outer verticalfinger grip ribs 50.

: In the form of the invention shown in FIGS. 6, 7 and 8, the inner capis the same as that shown in FIGS. 1 to 5 and need not be furtherdescribed. The outer or overcap 18a is similar to the overcap 18 in itsinclusion of a top closing wall 34a with driving lugs 42, a dependingskirt36a and weakened wall section 38a terminating in an inward shoulder40a. The skirt 36a differs in that the cut out slots are omitted and theinner wall surface is provided with a circumferentially continuous arrayof spaced vertical teeth 54 for cooperation with the teeth 25 on theinner cap and the skirt may thus be squeezed. at any diametricallyopposed surface areas and the external surface of the skirt 36a may beknurled or provided with vertical finger grip ribs 56facilitating:manipulation.

The closure of either form is assembled by snapping together theinnerwcap and the overcap during which action thei'inward; shoulders 40of the overcap 18 and 40a of the overcapl8a will spread and then snapback beneath .the shoulders 38, 38a respectively, on the inner caps.This will position the teeth 25 on the inner cap.16 inwardly of theteeth 48 on the outer cap 18 per -mitting relative rotation in acounterclockwise direction of the overcap (FIG. 1). Likewise, the teeth25 of the inner cap will be spaced inwardly of the teeth 54 of theovercap 18a (FIG. 7). In both forms, with the driving lugs 42 out ofvertical lapping, the overcaps will rest essentially in line-contactwith the ribs 30 of the inner :caps'althoughthere may be light linecontact, with botltleszresting-one upon another in shelf storage orstacked in cases in warehouse storage, between the lower edges of thevertical faces 42a of the driving lugs 42 and the .topof the inner cap,and the upper edges of the vertical faces 32a of the driving lugs 32with the undersurface of the'overcap, such line contact being providedby the relieved surfaces 32b and 42b of the lugs 32, 42,respectively-Thus, there is little tendency for any frictional settingat these line contacts due to storage or other conditions andsubstantially all planar surface contact is eliminated.

With reference to FIG. 1, an attempt to open the container by rotatingthe overcap 18 in a counterclockwise direction will result in this cappart rotating relative to the inner cap since the teeth 48 are out ofengagement with the teeth 25. This rotation of the overcap will causethe relieved portions 32b and 42b, respectively, to ramp or ratchet overeach other. In doing so, the overcap will reciprocate between thepositions of FIGS. 1 and 5. Thus the vertical free space between theshoulders 26 and 40 on the'inner and outer caps, respectively, isselected to permit the vertical lapping of the teeth 32, 42 as in FIG. 5with theshoulder 40 flexed outwardly, as shown, and as the driving teethor lugs bypass one another, the inherent resiliency of the flexible wallsection '38 will cause the shoulder 40 to snap back beneath the shoulder26 as shown in FIG. 1. Such permissive rotation of the overcap isintended to discourage children from further efforts to open thecontainer. However, an adult will know that radial inward squeezingpressure on the skirt secctions 50 will force the teeth 48 inwardly toengage the teeth 25 and thus permit counterclockwise opening rotation ofthe inner cap in unison with the overcap for opening the con tainer.Reclosing of the container is accomplished by clockwise rotation of theovercap bringing the vertical surfaces 32a, 42a of the teeth 32, 42,respectively, into driving contact for threading the closure to thecontainer and clamping the sealing disc 22 against the lip of thecontainer. Instead of the cut out sections 44 on the overcap, the topclosing wall thereof may be formed of sufficient flexibility to bulgeand permit engagement between the teeth 25 and 48 for opening movementof the closure. Operation of the form of closure shown in FIGS. 6, 7 and8 is essentially the same as described above, except that the skirt 36aof the overcap may be gripped at any diametrical areas for causingengagement between the teeth 54 on the overcap and the teeth 25 on theinner cap. Also, in either form, the top closing wall of the overcap maybe given such flexibility as to contribute to the permissive vertical upand down movement of the overcap relative to the inner cap and thethickness of the skirt sections 46 of the overcap 18 may be varied torequire greater or less inward pressure to effect interengagementbetween the teeth 48 and 25 and the flexibility of the skirt 36a of theovercap 18a may be varied for the same purposes.

After initial filling, the containers are closed and sealed in automaticcapping machines which apply relatively high torque to the overcapresulting in the vertical driving faces 42a of the teeth 42 on theovercap abutting the vertical faces 32a of the teeth 32 on the inner capand rotating the caps to thread the closure assembly to the containerwith tight compression of the disc 22 against the lip of the containerfor hermetically sealing the same. The driving lugs 32 and 42 areconstructed to resist any tendency toward stripping thereof under theapplied high torque. Thus, the substantially vertical abutment surfaces32a and 42a tend to prevent any overriding and bypassing of the lugsduring the capping machine closing and the relieved surfaces 32b and 42bserve to back up the abutting surfaces and resist any tendency towardstripping. At the same time, the relieved surfaces enter into thepermissive counterclockwise rotation of the outer cap as describedabove. Regardless of the amount of outside loading during automaticcapping or warehousing conditions, the cap will function properly on theapplication thereof to a container and the removal thereof. Duringcapping, the higher the applied force the greater the tendency towardstripping or ratcheting of the driving lugs. However, as the capassembly gets tighter on the container, the top of the inner cap tendsto distort upwardly which the capping machine head tends to keep the topof the overcap down, thus the top portionsare maintained together andthe abutting faces of the driving lugs are held in place with little orno tendency to ratchet or pop out of driving position.

We claim:

1. A safety closure assembly for a container having thread-likeformations below the container lip; and comprising an inner cap with atop closing wall to be sealed against the container lip and a dependingskirt with external vertical rib means providing teeth and with internalthread-like formations cooperable with the thread-like formations on thecontainer for closing and sealing the container upon rotation in onedirection and for opening the container upon rotation in the oppositedirection; and an outer cap with a top wall overlying the top wall ofthe inner cap and a depending skirt encircling the depending skirt ofthe inner cap and having internal rib means providing teeth normallyspaced outwardly from the teeth on the skirt of the inner cap to permitrotation of the outer cap relative to the inner cap in the openingdirection of rotation; means trapping the outer cap on the inner capwith permissive relative vertical movement between the top walls of theinner and outer caps; the adjacent enclosed wall surfaces of the innerand outer caps having the major portions thereof spaced apart a certaindistance, circumferentially spaced projecting lugs integrally formed onthe opposed adjacent enclosed wall surfaces of said inner and outer capswith initially engageable abutment driving surfaces for rotating thecaps in unison in the closing direction of rotation initially inautomatic capping machines and subsequently by hand after initialopening of the container, and each of said lugs on said inner and outercaps being of substantially the same vertical height as said certainspaced-apart distance of said adjacent enclosed wall surfaces and beingrelieved from the free edge of the abutment driving surface leaving anedge surface of minimum extent at the adjacent surface of a cap topwall; and the skirt of the outer cap being sufficiently flexible atleast at generally diametral areas for finger pressure thereon to shiftthe teeth of the outer cap inwardly into engagement with the teeth ofthe inner cap for rotation of both caps in unison in the openingdirection and the outer cap being rotatable in the opening directionindependently of the inner cap in the absence of sufficient fmgerpressure thereon and with the relieved surfaces of the lugs ratchetingover the lugs on the inner cap with the permissive relative verticalshifting of the cap top walls.

2. An assembly as claimed in claim 1, wherein opposed peripheral arcuatesections of the top wall of the outer cap are slotted to enhance theflexibility of the subjacent sections of the skirt for finger pressureapplication and wherein the teeth are carried by said subjacentsections.

3. An assembly as claimed in claim 1, wherein opposed peripheralsections of the skirt of the outer cap carry the inwardly projectingteeth and are of reduced cross section to afford flexibility for fingerpressure application thereto.

4. An assembly as claimed. in claim 1, wheren the trapping means betweenthe inner and outer caps comprises cooperating shoulder means at thefree edges of the cap skirts spaced axially apart a distance to assistin the vertical movement of the outer cap and top wall during ratchetingof the lugs as the outer cap is rotated in the opening directionindependently of the inner cap.

5. An assembly as claimed in claim 4, wherein the cooperating shouldermeans includes inwardly projecting shoulders at the free edge of theskirt of the outer cap resiliently maintained in position below shouldermeans at the free edge of the skirt on the inner cap.

6. An assembly as claimed in claim 5, wherein the skirt of the outer capis reduced in cross section adjacent the shoulder means for theresilient maintenance thereof in position and permitting outward flexingthereof against the adjacent shoulder means during ratcheting of thelugs.

7. An assembly as claimed in claim 1, wherein the teeth on the skirts ofthe inner and outer caps are disposed substantially completelytherearound and wherein the skirt of the outer cap is of substantiallyuniform flexibility enabling finger pressure application thereto at anydiametral areas therearound.

8. An assembly as claimed in claim 7, wherein cooperating shoulder meansat the free edges of the cap skirts traps together the caps with axialspacing between the shoulder means permitting vertical move ment of theouter cap during ratcheting of the lugs as the outer cap is rotated inthe opening direction independently of the inner cap.

9. An assembly as claimed in claim 8, wherein the wall of the skirt ofthe outer cap adjacent the shoulder means thereon is of reducedthickness permitting the shoulder means to be urged outwardly duringupward movement of the outer cap on ratcheting of the lugs and toresiliently return to normal position upon downward movement of theouter cap.

* =l l =l

1. A safety closure assembly for a container having thread-likeformations below the container lip; and comprising an inner cap with atop closing wall to be sealed against the container lip and a dependingskirt with external vertical rib means providing teeth and with internalthread-like formations cooperable with the thread-like formations on thecontainer for closing and sealing the container upon rotation in onedirection and for opening the container upon rotation in the oppositedirection; and an outer cap with a top wall overlying the top wall ofthe inner cap and a depending skirt encircling the depending skirt ofthe inner cap and having internal rib means providing teeth normallyspaced outwardly from the teeth on the skirt of the inner cap to permitrotation of the outer cap relative to the inner cap in the openingdirection of rotation; means trapping the outer cap on the inner capwith permissive relative vertical movement between the top walls of theinner and outer caps; the adjacent enclosed wall surfaces of the innerand outer caps having the major portions thereof spaced apart a certaindistance, circumferentially spaced projecting lugs integrally formed onthe opposed adjacent enclosed wall surfaces of said inner and outer capswith initially engageable abutment driving surfaces for rotating thecaps in unison in the closing direction of rotation initially inautomatic capping machines and subsequently by hand after initialopening of the container, and each of said lugs on said inner and outercaps being of substantially the same vertical height as said certainspaced-apart distance of said adjacent enclosed wall surfaces and beingrelieved from the free edge of the abutment driving surface leaving anedge surface of minimum extent at the adjacent surface of a cap topwall; and the skirt of the outer cap being sufficiently flexible atleast at generally diametral areas for finger pressure thereon to shiftthe teeth of the outer cap inwardly into engagement with the teeth ofthe inner cap for rotation of both caps in unison in the openingdirection and the outer cap being rotatable in the opening directionindependently of the inner cap in the absence of sufficient fingerpressure thereon and with the relieved surfaces of the lugs ratchetingover the lugs on the inner cap with the permissive relative verticalshifting of the cap top walls.
 1. A safety closure assembly for acontainer having thread-like formations below the container lip; andcomprising an inner cap with a top closing wall to be sealed against thecontainer lip and a depending skirt with external vertical rib meansproviding teeth and with internal thread-like formations cooperable withthe thread-like formations on the container for closing and sealing thecontainer upon rotation in one direction and for opening the containerupon rotation in the opposite direction; and an outer cap with a topwall overlying the top wall of the inner cap and a depending skirtencircling the depending skirt of the inner cap and having internal ribmeans providing teeth normally spaced outwardly from the teeth on theskirt of the inner cap to permit rotation of the outer cap relative tothe inner cap in the opening direction of rotation; means trapping theouter cap on the inner cap with permissive relative vertical movementbetween the top walls of the inner and outer caps; the adjacent enclosedwall surfaces of the inner and outer caps having the major portionsthereof spaced apart a certain distance, circumferentially spacedprojecting lugs integrally formed on the opposed adjacent enclosed wallsurfaces of said inner and outer caps with initially engageable abutmentdriving surfaces for rotating the caps in unison in the closingdirection of rotation initially in automatic capping machines andsubsequently by hand after initial opening of the container, and each ofsaid lugs on said inner and outer caps being of substantially the samevertical height as said certain spacedapart distance of said adjacentenclosed wall surfaces and being relieved from the free edge of theabutment driving surface leaving an edge surface of minimum extent atthe adjacent surface of a cap top wall; and the skirt of the outer capbeing sufficiently flexible at least at generally diametral areas forfinger pressure thereon to shift the teeth of the outer cap inwardlyinto engagement with the teeth of the inner cap for rotation of bothcaps in unison in the opening direction and the outer cap beingrotatable in the opening direction independently of the inner cap in theabsence of sufficient finger pressure thereon and with the relievedsurfaces of the lugs ratcheting over the lugs on the inner cap with thepermissive relative vertical shifting of the cap top walls.
 2. Anassembly as claimed in claim 1, wherein opposed peripheral arcuatesections of the top wall of the outer cap are slotted to enhance theflexibility of the subjacent sections of the skirt for finger pressureapplication and wherein the teeth are carried by said subjacentsections.
 3. An assembly as claimed in claim 1, wherein opposedperipheral sections of the skirt of the outer cap carry the inwardlyprojecting teeth and are of reduced cross section to afford flexibilityfor finger pressure application thereto.
 4. An assembly as claimed inclaim 1, wheren the trapping means between the inner and outer capscomprises cooperating shoulder means at the free edges of the cap skirtsspaced axially apart a distance to assist in the vertical movement ofthe outer cap and top wall during ratcheting of the lugs as the outercap is rotated in the opening direction independently of the inner cap.5. An assembly as claimed in claim 4, wherein the cooperating shouldermeans includes inwardly projecting shoulders at the free edge of theskirt of the outer cap resiliently maintained in position below shouldermeans at the free edge of the skirt on the inner cap.
 6. An assembly asclaimed in claim 5, wherein the skirt of the outer cap is reduced incross section adjacent the shoulder means for the resilient maintenancethereof in position and permitting outward flexing thereof against theadjacent shoulder means during ratcheting of the lugs.
 7. An assembly asclaimed in claim 1, wherein the teeth on the skirts of the inner andouter caps are disposed substantially completely therearound and whereinthe skirt of the outer cap is of substantially uniform flexibilityenabling finger pressure application thereto at any diametral areastherearound.
 8. An assembly as claimed in claim 7, wherein cooperatingshoulder means at the free edges of the cap skirts traps together thecaps with axial spacing between the shoulder means permitting verticalmovement of the outer cap during ratcheting of the lugs as the outer capis rotated in the opening diRection independently of the inner cap.